Abstract

The two-dimensional electron gas formed at LaAlO3/SrTiO3heterointerfaces exhibits a variety of interesting physical properties. Herein, we report on tunable conductivity at LaAlO3/SrxCa1−xTiO3heterostructures. By changing the Sr content in the SrxCa1−xTiO3 (0 ≤ x ≤ 1) layers, the orthorhombicity of the films, which inevitably accompanies TiO6 octahedral distortions in the unit cells, could be varied. As a result, the interfacial conductivity can be tuned over 6 orders of magnitude. We suggest that the use of pseudosubstrates with chemical substitution or alloying is a promising route to finely tune conductivity at oxide heterointerfaces.

Received 01 August 2012Accepted 17 December 2012Published online 07 January 2013

Acknowledgments:

This work was financially supported by KIST research programs (Grant Nos. 2E22731 and 2V02530). H.W.J. acknowledges the financial support of the National Research Foundation of Korea Grant funded by the Korean Government (NRF-2012-M3C1A1-048860).